Controllable truck lock for crawler tractors



June 20,1944. C, E, JONEg 2,351,685

CONTROLLABLE TRUCK LOCK FOR CRAWLER TRACTORS Filed Oct. 20, 1941 4 Sheets-Sheet l AT ORNEYS June 2o, 1944. C E, JONES 2,351,685

CONTROLLBLE TRUCK LOCK FOR CRAWLER TRACTORS Filed 001;. 20, 1941 4 Sheets-Sheet? ATTORNEYS l June 20,

c. E. .JONES CONTROLLABLE TRUCK LOCK FOR CRAWLER TRACTORS 4 Sheets-Sheet 3 Filed OCT.. 20, 1941 VINVENTOR QA@ ATTORNEYS June 20, 1944. C, E, JQNES 2,351,685

CONTROLLABLE TRUCK LOCK FOR CRAWLER TRACTORS Filed Oct. 20, 1941 4 Sheets-Sheet 4 INVENTOR A TORNEIYS Patented June 20, 1944 CONTROLLABLE TRUCKIAOCK FOR CRAWLER TRACTORS Cecil E. Jones, Lima, Ohio Application October 20, 1941, Serial No. 415,696

(Cl. 18S- 30) l2. Claims.

This invention relates to controll-able truck locking mechanism for crawler tractors of the type commonly used to mount load handling equipment such as power shovels, cranes and the like. Such truck locks are of use in preventing undesired movement of the machine on the ground, especially during operation of the machine, as in digging with a power shovel.

For the purpose above specified it has been known to employ ratchet devices having four positions of adjustment providing, respectively, for locking of the crawler truck against movement alternatively in the forward or backward directions, simultaneous locking against movement in both directions, and freeing of the truck for movement in either direction.

Various of the prior ratchet mechanisms are subject to disadvantages, such as unreliable or inaccurate operation; impossibility of or inconvenience in initial adjustment or in subsequent adjustment to compensate for wear; and undue multiplication of actuating and control parts, such as links and the like.

It is with these diiculties that the present invention is principally concerned, the arrangement hereof being unusually simple in structure and operation, notwithstanding that provision is made for four different normal operating set' tings, as well as adjustment, and further being exceptionally rugged, so as to effectively carry the heavy loads of service. I

Yground through the vertical propel shaft shown in Figure l, this View being taken in the same direction as Figure l;

Figure 3 is a view on the scale of Figure 2 but taken at right angles to Figure 2 and illustrating many of the `parts in vertical section; and

Figures 4 and 5 arelviews of some parts taken similarly to Figure 3 but illustrating different operating positions.

Referring first to Figure 1, the outline of a pair of crawler treads 6-1 is shown in dot and dash lines, These treads are associated with a crawler truck generally indicated at 8, which truck in turn serves to support the superimposed cab and machinery, including the power plant,

for which purpose a rotating base 9 is mounted on the truck by means of a center pin l0 and rollers (not shown) which ride on track 8a, so that the entire upper part of the machine may be rotated with reference to the truck and trea 8 and E-'L i The machine is adapted to be driven on the Il which carries a gear I2 at its upper end for cooperation with driving mechanism which need not be'considered herein. At its lower end shaft Il carries a bevel gear I3 meshing with bevel gear M'rnounted on the central section l5 of the horizontal propel shaft.

Clutch devices, one of which is generally indicated at I6, serve to couple shaft l5 with shaft extensions |5a and 15b which extensions, in turn,

, are connected with the tread sprockets (not In accordance with another aspect of the'invention, provision is made for adjustment of the positions of the ratchets with reference to each other and with reference to the control member, whereby proper setting of the ratchets may initially be provided and may be maintained.

Although the ratchet mechanism and control therefor, as provided by this invention, is applicable to many different` situations, the arrangement is vpeculiarly suited to power machinery, such for example as shovels and cranes, for reasons brought out more fully hereinafter in the following description, referring to the accom'- panying drawings, which illustrate the invention in a typical application to a load handling machine mounted on a vcrawler tractor.

In the drawings- Figure 1 is an end view of portions of a power handling machine, with parts shown in section in the transverse vertical plane containing the center pin mounting of the rotating base ofthe machine;

Figure `2 is an .enlarged view of some parts shown) usually through a chain drive, these parts not being illustrated in detail herein since they form no part of the present invention per se. lit may be noted, however, that the clutch units it are provided primarily for the purpose of steering, this function being achieved by control mechanism adapted alternativelyto engage oneV or the other of theclutches I6 so as to drive one or the other of the treads 6 and 1. Ordinarily, each device I6 has three positions of adjustment. In one such position, the drive is transmissible therethrough to the crawler sprocket at that side of the machine, in another position the clutch is disconnected from the central shaft l5 and the associated shaft extensions (la or `15b) is locked as against movement, and in the third position, usually intermediate the first two, the shaft extension is neither locked nor coupled to the drive.

Control of the clutch units is secured by a lever l1 connected with the vertical push-pull member I8 extended through the center pin mounting and coupled with arm ,I9 mountedon the control shaft 2B, from which suitable connections (not shown) are extended to the clutch units at opposite sides of the machine. As is known in this art, with this control, the driving :sprockets for both treads may be actuated, or

pel shaft I5 carries a ratchet wheel l2|V 'having'r peripherally spaced teeth 22 shaped to cooperate with ratchets 23 and 24 operating in opposite directions. Ratchet 23 is mounted for free pivotal movement on a shaft 25, the shaft being journalled as indicated at 2,6 and 21. The shaft is extended to carry a ratchet lifter comprising a sleeve@ having an arm 28projecting therefrom to engage abutmentfZ-S formed on the ratchet, so-that upward-movement' of arm 2lir will raise the ratchetand disengage it from the' wheel2|. Movement oi the ratchet lifterfis eficcted through bifurcatedarm`30 projecting from sleeve S and servingto rotatively mount` a pin 3| having a transverse threaded aperturelfor coopera-tion -with/ link; 32.` f

At'the oppositeside'oftlie WheelZl the ratchet 24 i's similarly-mounted onashaft 33, the shaft having anvextensioncarryinga sleeve S', with a liftertli cooperating-with an abutment35 projecting fromv the ratchet,U and further having a bifurcatedarmr 36-for mounting' pin" 3`| which cooperates withthreaded'link'38:

Theftwo links V32"a'.nd'38 are pivoted by pins 32a and nStatoA acentral yoke 39 which is adapted to be -moved ina vertical direction by'means of the control tube 4U surrounding the push rod 4I8 and extending upwardly/through vertical' propel shaft and the center 'pin' l0. `A'control lever 4|, pivoted'fon a rlxed 'bracket 'at 42, cooperatesV wthtthe upper endof controltub'e'lll and servesV to raise/'and' lower the"tube,r the interconnection between the `control'l'ever 'and the tube being arranged toY providefor free relati'i're'rotati'on"A about the axis of the center pin |',`s`o'that rota;` tive movement of the base assembl'ytis accom' modatedf Adjustment fof the control'lever is maintained'by'employrnent` of a 'notched' quadrant 43. As shown, theVV quadrant has "four'" notches; corresponding'tothe'four positions of adjustment' ofthe 'ratchet mechanismV referred to morefully'hereinafter- Anarm' 44 projects from4 `and moves with the ratchet lifter parts 34, 36 (at'the right-hand side in Figures3 to 5), such'motion being independent of ratchet 24 except when the'lifter arm 34 con-` tacts the ratchet abutment '35. Arm 44 is connected by link-45 Ywith'an varm46 which is rigid With'ratchet'23 at the opposite side. VLink 45 has lost-motion slots 41 cooperating with thepinsy Vlfand 49, by means of which the link is coupled with arms 44 and'46'."

In *considering* the `operationv of the `1ratchet mechanism,A it shouldbe kept in 'mind'thatralthough the ratchet lifter-v arms 28 and 34 arev arranged for cooperation `with=abutrrients 29 and 35 onthe two ratchets to disengage the latter upon upward movement ofthe lifters, the ratchet lifters aremovable independently ofthe ratchets in allpositions below the point Iof engagement withl-the'ratchetabutments29 and 35. Gravity is thus-relied upon fori downwardA movement of the ratchets into engagement with the ratchet wheel 2|.

In Figure l, indicia are applied to the four notches of quadrant 43, such indicia indicating `the four positions of ratchet adjustment, the iirst two of which are shown in Figure 3 and the remaining two of which are illustrated, respectively, in Figures 4 and 5.

In position A, the control tube 40 is at the uppermost limit of its motion, and at that time both of the ratchet lifters 28 and 34 are operative toraise the ratchets (23 and 24) associated therewith. rllhis position is shownV in full lines in Figure 3, from which it will be seen that both of the ratchets are well clear of the ratchet wheel l 2|, ratchet 24 being lifted somewhat higher than ratchet 23.

Upon actuation of the control lever 4| to position B, the control tube 40 is caused to move: downwardly, with the result that ratchets 23 and i 24tale the-positions 'indicated in Figure 3 at.

23a 'andZB-. Ratchet 23'at this time is in engage-l1V ment' with the wheel I2 I", movement of ratchet 24 engage the-wheel.

Further downward movement of control'tul'ie 4B, accompanying movement of the control lever 4| to position C," permitsY ratchet 24 todrop to the position indicated in Figure 4, in which both ratchets are in engagement with'the WheelV 2|; From Figure 4- it will also beseen thatthe lifter f although the downwardi is still not sufcient toi 25 28 at the leftfhas moved downwardlyawa'y 'from' the cooperating ratchet abutment l 29:

From the above it will beseen that the three positions of adjustmentjust-describedare en?l tirely eiected by theratchet--lifters andV the' 'con'- trol tube which is coupled with the operating' handle 4|.' To ensureA freedom for;suchoperation` the cross link asis slotted sufficiently to permit* movement "between arm" 23 and arm is ofthelifterfor" Thus, in the rfull line position cf' Figure 3 (position A) theslotsd preventtrans:

40 'the required freedom of 46 of'ratchet ratchet 24:

mission of any force between armsll and 46. It will also be observed that are engaged; and in position D (Figure 5), ratchet ,Y 23 is disengaged and; ratchet 2,4 is engaged.

Referring againfto link 45 'and its 10st-motion y s1otsf4'|, it is'y pointed out that the required lost). motion may be secured from only la single slotl arranged at one end o f the 4link (instead of two.v

slots as herein illustrated), being thatthe Yeirtentof lost motion must be adequateto' permit the desired free operation ofthe` lifters as between any of positions A, B and C.

the only essential i The link, therefor'efcomes into operationfor,only` one out of the four positions of adjustment (poshv tionDX" l Y y The ymre'gomg arrangement'of the ratchet lift-J ers and other actuatingparts isv unusually simple1 as compared with 'prior double-acting four-.posi--` Y tion ratchet devices. In addition, for reliabili yq of'operation, it is of'advantage that only one out,"

as thel control tube'is moveddownwardly untilI position C is reached," as"v slots El in link 45 do notl positions of the ratchets. position D, however see M transmitting 'l A, both ratchets are disengaged; in position B, ratchet 23` is engaged jand ratchet 24 is dicen-1.V gaged; in positionC (Figure4), both ratchets-ff of the four positions relies upon a cross link between the ratchet mechanisms at opposite sides.

rectly coupled with yoke 39 by means of a link (32 or 38), which 4link is threaded into a pin (3| or 31) carried by the lifter mechanism. Ad-

justment of lifter 28 may be eiTected merely by removing pin 32a which interconnects link 32 with control yoke 39, and by screwingV link 32 up or downin pin 3| and then reconnecting the link with the control yoke. Adjustment at the opposite side may be effected in a similar manner.

In accordance with the foregoing, provision is made for adjustment so that the desired position ,u

of the ratchet lifters, and of the ratchets when raised by said litters, may quickly and accurately be established at the time of initial assembly.

Any service wear may also be compensated for in this Way. It may be mentioned that accuracy of adjustment is of importance for several reasons. For example, if one or both of the ratchets are not in full engagement in accordance with the intended operating setting, heavy loads might be transmitted through the operating and control connections.

structurally, the ratchet mechanism herein disclosed is not only simple in design but, in addition, the parts are strong and so relatively located as to take heavy loads without introducing undue bending moments or the like. Note, for example, that each ratchet (see ratchet 23 in Figures 2 and 3) is rotatively mounted on a supporting shaft, which shaft is carried in journals (26 and 21) located one at either side of the ratchet and immediately adjacent thereto.

I claim:

1. In a double-acting ratchet, in combination with a ratchet Wheel and with an upright vertically movable control member, a pair of operatively opposed ratchets associated with said wheel and each pivotally mounted for downward and upward swinging movement into and out of engagement with the ratchet wheel, respectively, for each ratchet a pivoted lifter having a'n abutment surface adapted to cooperate with a complementary surface on the ratchet for disengaging the ratchet upon upward pivotal movement of said lifter, and, for each lifter, a link coupled therewith and with the control member, the operating parts for each ratchet being arranged to provide for lifting of one ratchet prior to lifting of the other ratchet, upon movement of the control member in one direction.

2. A construction in accordance with claim 1 in which one of said ratchets and the lifter for the other ratchet are interconnected by a pivotal lost-motion link operative upon movement of the control member in one direction to transmit a ratchet disengaging movement to said one ratchet from the lifter associated with the other ratchet.

3. A construction in accordance with claim 1 in which one of said ratchets and the lifter for the other ratchet are interconnected by a pivotal 10st-motion link operative upon movement of the control member in one direction to transmit a ratchet disengaging movement to said one ratchet from the lifter associated with the other ratchet, the ratchet adjusting parts, including said lostmotion link, being arranged to provide four positions of adjustment of said ratchets upon upward and downward pivotal movement of the lifters, the highest position of said lifters providing foridisengagemen't of both ratchets, the next or second position of said lifters providing for engagement of one ratchet and disengagement of the other, the third position of said lifters providing for engagement of both ratchets, and the fourth position of said lifters providing for disengagement of said one ratchet and for engagement of said other ratchet.

4. In a` double-acting ratchet, in `combination with a ratchet wheel and with an upright vertically movable control member, a pair of operatively opposed ratchets associated with said wheel and each pivotally mounted for downward and upward swinging movement into and out of engagement |with the ratchet wheel, respectively, for each ratchet a pivoted lifter having an abutment surface adapted to cooperate with a complementaryl surface on the ratchet for disengaging -the ratchet upon upward pivotal movement of said lifter, for each lifter a link co-upled therewith and with the control member, and means cooperating with at least one of said links and providing for adjustment of the associated lifter device with respect to the control member.

5. For a crawler tractor, a truck lock including a pair of operatively opposed ratchets, a vertical push-pull member for controlling the positions of the ratchets, a separate operating connection between the control member and each of said ratchets including a link connected with the control member and having screw thread adjustment means for determining the position of that ratchet with reference to the vertical control member independently of the other ratchet.

6. For a crawler tractor, a truck lock including a pair of operatively opposed ratchets, a member for controlling the positions of the ratchets, a separate operating connection between the control member and each of said ratchets including, for each ratchet, separately adjustable means for determining the position of the ratchet with a given setting of the control member, whereby the relative position of the ratchets may Ibe altered with a given setting of the control member.

'7. In combination with a ratchet wheel, a pair of operatively opposed ratchets associated with said Wheel, each ratchet being pivotally mounted for swinging movement upwardly and downwardly between positions in and out'of cooperation With the ratchet wheel, an upright vertically movable control member for said ratchets, and mechanism associated with the control member and the ratchets for effecting different adjustments of the latter including, for each ratchet, a pivotally mounted lifter and a link connecting said lifter with said control member whereby the lifters for the two ratchets are pivotally moved upon vertical movement of the control member, each of said llfters and the ratchet with which it is associated ibeing provided with cooperating abutments adapted to interengage upon upward pivotal movement of the lifter to effect raising of the associated ratchet, said links and the associated parts of the adjustment mechanism being arranged to provide for lifting of one of said ratchets prior to the other, upon movement of the control member in one direction.

8. A construction in accordance with claim 'l and further incorporating a pivoted lost-motion lifter for the other of said ratchets,

positions of Ythe ratchetsfincluding. for .each

ratchet al lifter *movabley with l resizgect -to the ratchet but l adapted toabut the Lvrziizolvlevt 119911 'upward movement t0 transmit a ,Jiftnglfprce thereto, controlrmeans for raisingl` and lowering said lifters conjointly, the vratchets@and litters Joeing arrangedvto provide for liftingcof one ratchet prior to the other upon conjOnt upward .movement of the lifterps, whereby yin an upper ,position of adjustment the lifting members act tto disengage both ratchets, in the next lower or :second position of the lifters one ratchet is engaged and the other disengaged, and in a still lower third position both ratchets are engaged, and means operative upon conjoint downward :movement of the lifters from said third to a 20 'fzgistess d. (auch passion.of'isiainitrehei ,which was engaged'linl thesecond position, the other ratchet remaining engaged, .i

10. A Aconstruction in accordance Withclaim l 9 and' further interporating means for adjusting the A"osition of the lifters with respect to the control means.V

11.. A t construction ,accordance .wither l 9V and further incorporating means for adjusting the positionof the twolifters with respect tothe c control meansl independently of eachsiother,

whereby the relative position of the ratchets' is adjustable. ci l 1 12.Av4 construction in accordance n with claim 9 inrwhichsaid lastmeans comprises a lost-motion link connecting-the ratchet which isengagedvin .the second position with the lifters for the'other ratchet. I A

CECIL E. JONES. 

